Dissimilar friction stir spot welding of AA2024-T3/AA7075-T6 aluminum alloys under different welding parameters and media

• 作者: Gui-ju Zhang Cai-yuan Xiao Olatunj Oladimeji Ojo
• 来源期刊: 防务技术
• 年，卷（期）: 2021,（2）
• 页码范围: 531-544
• 页数: 14页
• 语种: 英文

摘要

This paper studies the friction stir spot welding of AA2024-T3/AA7075-T6 Al alloys in the ambient and underwater environments by clarifying the nugget features,microstructure,fracture and mechanical properties of the joints.The results show that the water-cooling medium exhibits a significant heat absorption capacity in the AA2024-T3/AA7075-T6 welded joint.Nugget features such as stir zone width,circular imprints,average grain sizes,and angular inter-material hooking are reduced by the water-cooling effect in the joints.Narrower whitish(intercalated structures)bands are formed in the under-water joints while Mg2Si and Al2CuMg precipitates are formed in the ambient and the underwater welded joints respectively.An increase in tool rotational speed(600-1400 rpm)and plunge depth(0.1-0.5 mm)increases the tensile-shear force of the welded AA2024-T3/AA7075-T6 joints in both the ambient and underwater environments.The maximum tensile-shear forces of 5900 N and 6700 N were obtained in the ambient and the underwater welds respectively.